string to acceptable filename

Posted on 1998-05-31
Last Modified: 2010-04-06
I need a procedure RemoveInvalidFileCharacters(var Inputstring: string);
which substitutes invalid characters (that is for a Windows 95 filesystem)
by spaces.
e.g.   'TESTname' -> 'TESTname'
e.g.  'éééxamp^^^le' ->     '   xamp   le'
Question by:miauw
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2

Accepted Solution

Edo082297 earned 100 total points
ID: 1349475
Hi Miauw,
  Here is your function. Note that Windows 95 will allow you to store filenames containing weird characters (other countries use these strange symbols; they even speak with them ;). You can also store filenames with special symbols like % and ^. You may not, however, use filenames that contain the following symbols: [\, /, :, *, ?, ", <, >, | ]. So, all we do is filter those out. If you want to block specific characters, you will have to add it to the filter list. Note that the function as it stands filters out some characters that are actually legal in a filename, but strange in the context of a filename (such as ^).

procedure TForm1.Button1Click(Sender: TObject);
  Edit2.Text := RemoveInvalidFileCharacters(edit1.Text);

function TForm1.RemoveInvalidFileCharacters(const AFileName : string): String;
  i : integer;
  Result := AFileName;

  // access violation will occurr in first iteration of for loop with blank string
  if Length(AFileName) = 0 then

  for i := 0 to Length(AFileName) do
    if not (AFileName[i] in ['0'..'z'])
        or (AFileName[i] in ['\', '/', ':', '*', '?', '"', '<', '>', '|']) then
      Result[i] := ' '




Author Comment

ID: 1349476
Thanks, I was ready by now, but you answered the question before I could
delete it, so I will give you A: Excellent.

Expert Comment

ID: 1349477
Thanks, Miauw!

Featured Post

Technology Partners: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
Intraweb download file link ? 1 167
URL for downloading Google Chrome for Win XP 2 235
How to renew a Delphi rad-studio licence? 5 77
DBCtrlGrid, Delphi, Scroll 8 59
This article explains how to create forms/units independent of other forms/units object names in a delphi project. Have you ever created a form for user input in a Delphi project and then had the need to have that same form in a other Delphi proj…
Hello everybody This Article will show you how to validate number with TEdit control, What's the TEdit control? TEdit is a standard Windows edit control on a form, it allows to user to write, read and copy/paste single line of text. Usua…
Although Jacob Bernoulli (1654-1705) has been credited as the creator of "Binomial Distribution Table", Gottfried Leibniz (1646-1716) did his dissertation on the subject in 1666; Leibniz you may recall is the co-inventor of "Calculus" and beat Isaac…
Finds all prime numbers in a range requested and places them in a public primes() array. I've demostrated a template size of 30 (2 * 3 * 5) but larger templates can be built such 210  (2 * 3 * 5 * 7) or 2310  (2 * 3 * 5 * 7 * 11). The larger templa…

733 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question